If you say 'He called me an idiot', it's an example of a noun phrase - 'an idiot' - being used as an object complement. That's a complement, not a 'compliment', needless to say. It's rarely a compliment to be called an idiot.

Here are some examples of noun clauses used as object compliments. The judges will announce the winner whoever brought the green velvet cake. The assessment committee announced the problem us refusing to try new procedures. Most critics consider one theme of the story what you wrote about in your final paragraph. You may call your husband whatever you wish. I declare the problem that you do not want to learn about grammar. The committee has announced the winner whoever wrote the essay on noun clauses.